best xml parser to use

Hi

I have a particular problem to solve:

I have an xml batch file that contains individual xml invoices. I need to extract these xml invoices one at a time and
place them on a message queue i.e. I just need to get all the data between the invoice start and end tags put it
in a string and place it on a message queue (validation occurs on the invoice itself on the receiver side).

What is likely to be my best approach, DOM (unlikely I guess), SAX, StAX or simply writing a java program using indexOf, in terms of performance ?


TIA Peter